Pedal feeling adjustable electronic control hydraulic braking system and vehicle with pedal feeling adjustable electronic control hydraulic braking system

Abstract

The invention discloses a pedal feeling adjustable electronic control hydraulic brake system which comprises a brake pedal, a brake master cylinder, a pedal simulator, an electromagnetic valve, an auxiliary master cylinder and a driving structure used for driving the auxiliary master cylinder. The brake master cylinder is connected with the pedal simulator and the auxiliary master cylinder through the electromagnetic valve and the hydraulic loop, the driving structure can adjust the pressure of the auxiliary master cylinder, the auxiliary master cylinder is controlled by the electromagnetic valve to discharge brake fluid with different volumes to the brake master cylinder, and the brake fluid generates different pressures after entering the brake master cylinder. And then the signals are transmitted into the pedal simulator to simulate different pedal feelings. Compared with a single pedal feeling mode of an original brake-by-wire system, the brake-by-wire system can achieve switching of multiple pedal feeling modes, and the requirements of consumers for different brake foot feelings in different driving scenes are met.

Description

Technical Field

[0001] The present invention relates to the technical field of automotive braking, and particularly to an electronically controlled hydraulic braking system with adjustable pedal feel and a vehicle thereof. Background Art

[0002] With the development of new energy vehicles and active safety braking technology, the technology of electronically controlled hydraulic braking systems has also developed. For a pedal feel simulator in an existing electronically controlled braking system, its working principle is a mechanical device that realizes force feedback through a combination of springs of various different specifications, simulating the resistance and stroke of the brake pedal, so that when the brake pedal of the automotive braking system is depressed, a certain pressure and feedback are generated through a hydraulic circuit, enabling the driver to perceive the working state of the braking system. This can improve the driver's perception and control of the vehicle's braking performance, so as to more accurately adjust the braking force, reduce misoperations during braking, and improve driving safety and comfort.

[0003] To realize the simulation of the resistance and stroke of the brake pedal, the pedal feel simulator needs to completely draw the curves of the simulated pedal force and pedal stroke, configure the spring combination in the pedal feel simulator according to the curves of the simulated pedal force and pedal stroke, enable the driver to feel the braking force and changes, and enhance the driver's sense of control. The brake pedal feel simulation technology can be applied to various types of vehicles, including traditional internal combustion engine vehicles and new energy vehicles, giving the driver a realistic braking feedback.

[0004] For the existing electronically controlled braking system and its pedal feel simulator, on the premise of excluding factors such as the decline in hardware aging performance, once the spring specifications and combinations in the pedal feel simulator are determined, the curves of the simulated pedal force and pedal stroke will no longer change. With the development of technology and the improvement of living standards, the market requires different strategies for pedal feel simulation for different vehicle models, and the same vehicle model also has requirements for different pedal feel modes, such as comfort mode and sport mode. The traditional pedal feel simulator is limited by its own structure and is doomed to be unable to flexibly adjust the curves of the simulated pedal force and pedal stroke, and its applicability cannot meet the requirements.

[0005] For example, an electronically controlled hydraulic braking system disclosed in Chinese Patent CN 112389401 includes a fuel tank, a first cylinder, a second cylinder, a driving member, an inlet valve, a wheel cylinder, a first liquid path, a first isolation valve, a second liquid path, and an outlet valve. The driving member drives the first piston of the second cylinder to move. The wheel cylinder is connected to the inlet valve. The first liquid path is located between the first cylinder and the inlet valve. The first isolation valve is located on the first liquid path. The second liquid path is provided between the second cylinder and the inlet valve. A forward control valve and a reverse control valve are provided on the second liquid path. The outlet valve is connected between the wheel cylinder and the fuel tank; it cannot well simulate different types of brake pedal feel to meet different vehicle models, and the cost is relatively high. Summary of the Invention

[0006] In view of the deficiencies of the prior art, the present invention provides an electronically controlled hydraulic braking system with adjustable pedal feel and a vehicle thereof, which can realize the switching of multiple pedal feel modes and meet the requirements of consumers for different braking foot feelings in different driving scenarios.

[0007] In order to solve the above technical problems, the technical solution adopted by the present invention is as follows:

[0008] An electronically controlled hydraulic braking system with adjustable pedal feel includes a brake pedal, a master cylinder, a pedal simulator, a solenoid valve, a secondary master cylinder, and a driving structure for driving the secondary master cylinder. The brake pedal is correspondingly connected to the master cylinder. The master cylinder is connected to the pedal simulator and the secondary master cylinder through a solenoid valve and a hydraulic circuit. The driving structure can adjust the pressure of the secondary master cylinder, and the solenoid valve controls the secondary master cylinder to discharge different volumes of brake fluid to flow to the master cylinder. After the brake fluid enters the master cylinder, different pressures are generated, and then transmitted to the inside of the pedal simulator to simulate different pedal feelings.

[0009] The driving structure includes a motor and a transmission mechanism connected to the piston of the secondary master cylinder. A gear connected to the transmission mechanism is provided on the rotating shaft of the motor.

[0010] The pedal simulator is connected to the hydraulic circuit through a simulator branch. The simulator branch is connected to the master cylinder. The secondary master cylinder is connected to the hydraulic circuit through a secondary master cylinder branch. Pressure sensors are provided on both the simulator branch and the secondary master cylinder branch.

[0011] The motor is a permanent magnet synchronous motor.

[0012] A pedal travel sensor is provided between the brake pedal and the master cylinder.

[0013] A pedal simulator valve is provided on the simulator branch.

[0014] Master cylinder isolation valves are provided on both the simulator branch and the hydraulic circuit directly connected to the master cylinder. A secondary master cylinder isolation valve is provided on the secondary master cylinder branch.

[0015] When the pedal simulator simulates the switching of different pedal feelings, the master cylinder isolation valve is in the closed state.

[0016] The secondary master cylinder isolation valve includes a secondary master cylinder isolation valve I and a secondary master cylinder isolation valve II. The secondary master cylinder isolation valve I controls the connection between the secondary master cylinder branch and the hydraulic circuit. The secondary master cylinder isolation valve II controls the connection between the secondary master cylinder branch and the simulator branch. When the pedal simulator simulates the switching of different pedal feelings, the secondary master cylinder isolation valve I is in the closed state, and the secondary master cylinder isolation valve II is in the conducting state.

[0017] A vehicle includes the electronically controlled hydraulic braking system with adjustable pedal feel.

[0018] Compared with the prior art, the present invention has the following advantages:

[0019] 1. Adapt to diverse market demands: Compared with the single pedal feel mode of the original wire-controlled braking system, this system can switch between multiple pedal feel modes, meeting consumers' requirements for different braking foot feelings in different driving scenarios and enhancing driving pleasure.

[0020] 2. Save manufacturing costs: Compared with the principle of simulating pedal feel in the original wire-controlled braking system, this system can achieve simulating different braking foot feelings at low cost by influencing the pressurization degree of the permanent magnet synchronous motor on the secondary master cylinder through different control strategies without changing the structure of the pedal simulator.

[0021] 3. Improve the applicability of the wire-controlled braking system: Compared with the principle of simulating pedal feel in the original wire-controlled braking system, this system can achieve different control algorithms acting on the permanent magnet synchronous motor. The pressure generated in the secondary master cylinder is transmitted to the pedal simulator through the hydraulic circuit. Different curves of simulated pedal force and pedal stroke will be formed under different compression states of the pedal simulator. This characteristic enables the wire-controlled braking system to be potentially applied to different types of vehicles, such as off-road vehicles, sports cars, racing cars, etc., improving the applicability of the wire-controlled braking system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The following briefly describes the content expressed in each drawing of this specification and the marks in the drawings:

[0023] Figure 1 is a schematic diagram of the hydraulic braking system of the present invention.

[0024] Figure 2 is a schematic diagram of the simulated pedal force-stroke curve of the present invention.

[0025] Figure 3 is Figure 2 an enlarged curve schematic diagram of the curve within a stroke of 0 - 20 mm.

[0026] In the figure:

[0027] 1. Brake pedal, 2. Pedal stroke sensor, 3. Brake master cylinder, 4. Pedal simulator, 5. Pedal simulator valve, 6. Test normally open valve, 7. Master cylinder isolation valve I, 8. Master cylinder isolation valve II, 9. Secondary master cylinder isolation valve I, 10. Secondary master cylinder isolation valve II, 11. Permanent magnet synchronous motor, 12. Secondary master cylinder. DETAILED DESCRIPTION OF THE INVENTION

[0028] The following further elaborates on the specific implementation manners of the present invention in detail by describing the embodiments with reference to the drawings.

[0029] As Figure 1As shown, the pedal feel adjustable electronically controlled hydraulic braking system includes a brake pedal 1, a master cylinder 3, a pedal simulator 4, a set of brake wheel cylinders, solenoid valves, a secondary master cylinder 12, and a drive structure for driving the working pressure adjustment of the secondary master cylinder; the drive structure drives the pressure adjustment of the secondary master cylinder, and the pressure of the secondary master cylinder is transmitted to the pedal simulator to simulate different pedal feels.

[0030] The brake pedal 1 and the master cylinder 3 are correspondingly connected and arranged. The master cylinder is connected to the pedal simulator and the secondary master cylinder through solenoid valves and a hydraulic circuit; the master cylinder and the pedal simulator are both connected to a set of brake wheel cylinders through a hydraulic circuit. There are four brake wheel cylinders in a set, and the cavity of the secondary master cylinder is connected to the hydraulic circuit.

[0031] By controlling the solenoid valves and the drive structure, different volumes of brake fluid discharged from the secondary master cylinder are controlled to flow to the master cylinder. After the brake fluid enters the master cylinder, different pressures are generated, which are then transmitted to the inside of the pedal simulator to generate different "master cylinder stroke - force" relationships; as Figure 2 shown, thus simulating different pedal feels.

[0032] The drive structure includes a motor and a transmission mechanism connected to the piston of the secondary master cylinder. The transmission mechanism is preferably a rack, and a gear meshing with the rack is provided on the rotating shaft of the motor. The motor is preferably a permanent magnet synchronous motor 11. Or the drive structure adopts an existing electric push structure connected to the piston of the secondary master cylinder.

[0033] The system of the present invention can realize, without changing the structure of the pedal simulator, influencing the pressurization degree of the permanent magnet synchronous motor on the secondary master cylinder through different control strategies, and then realizing the low - cost simulation of the braking foot feel in different modes, so as to meet the requirements of consumers for different braking foot feels in different driving scenarios.

[0034] The pedal simulator 4 is connected to the hydraulic circuit through a simulator branch. The simulator branch is connected to the master cylinder. The secondary master cylinder is connected to the hydraulic circuit through a secondary master cylinder branch. Pressure sensors are provided on both the simulator branch and the secondary master cylinder branch.

[0035] The master cylinder, the pedal simulator, and the secondary master cylinder are all connected to a test branch. A normally open test valve 6 is provided on a test branch connected to the master cylinder for convenient test operation.

[0036] Furthermore, a pedal stroke sensor 2 is provided between the brake pedal and the master cylinder; a pedal simulator valve 5 is provided on the simulator branch.

[0037] Master cylinder isolation valves are provided on both the simulator branch and the hydraulic circuit directly connected to the master cylinder, and a secondary master cylinder isolation valve is provided on the secondary master cylinder branch; specifically, a master cylinder isolation valve I 7 is provided on the hydraulic circuit directly connected to the master cylinder, and a master cylinder isolation valve II 8 is provided on the simulator branch.

[0038] The secondary master cylinder isolation valve includes a secondary master cylinder isolation valve I 9 and a secondary master cylinder isolation valve II 10; the secondary master cylinder isolation valve I controls the connection between the secondary master cylinder branch and the hydraulic circuit, and the secondary master cylinder isolation valve II controls the connection between the secondary master cylinder branch and the simulator branch; when the pedal simulator simulates different pedal feel switches, the secondary master cylinder isolation valve I is in the closed state, the secondary master cylinder isolation valve II is in the conducting state, and the master cylinder isolation valve is in the closed state;

[0039] By controlling the rotation of the permanent magnet synchronous motor, driving the rack of the secondary master cylinder to move and thus increasing the pressure of the secondary master cylinder, combined with the valve to form a closed circuit, the pressure in the secondary master cylinder is conducted to the pedal simulator through the hydraulic circuit; when the driver has a braking demand, since the pedal simulator has been compressed by a certain distance by the brake fluid in the circuit, the pedal force felt by the driver when continuing to step on the brake pedal will increase, simulating different brake pedal feels.

[0040] A preferred specific example of the present invention is:

[0041] The electronically controlled hydraulic braking system with adjustable pedal feel can effectively simulate different types of brake pedal feels to meet different vehicle models, as well as the braking pedal feel requirements in different driving modes and scenarios, without changing the original structure of the pedal feel simulator and saving material costs.

[0042] The system includes a brake pedal 1, a pedal travel sensor 2, a brake master cylinder 3, a master cylinder pressure sensor P2, a secondary master cylinder 12, a secondary cylinder pressure sensor P1, a pedal simulator 4, a pedal simulator valve 5, a test normally open valve 6, a master cylinder isolation valve, a secondary master cylinder isolation valve, a permanent magnet synchronous motor 11, and a circuit pressure increasing control valve (ISO1, ISO2, ISO3, ISO4) and a circuit pressure reducing control valve (DUMP1, DUMP2, DUMP3, DUMP4) provided on the circuit connected to each brake wheel cylinder.

[0043] The working principle of the pedal feel simulator to simulate different pedal feels is as follows: when it is necessary to switch the pedal feel mode or apply the electronic brake system to other vehicles, the characteristics of the electronic brake system can be utilized to control the rotation of the permanent magnet synchronous motor, drive the rack of the secondary master cylinder to move and thus increase the pressure of the secondary master cylinder, combined with the on-off of different valves in the circuit, and finally conduct the pressure of the secondary master cylinder to the pedal simulator through the hydraulic circuit. When the driver has a braking demand, since the pedal simulator has been compressed by a certain distance by the brake fluid in the hydraulic circuit, the pedal force felt by the driver when continuing to step on the brake pedal will increase.

[0044] Its working process is as follows: when switching the pedal feel mode, the system receives a control signal, and the circuit pressure increasing control valves (ISO1, ISO2) are energized and actuated. The valves become closed, and the brake fluid will not enter the wheel cylinder to pressurize and cause accidental braking. At the same time, the secondary master cylinder isolation valve is energized, and the valve changes to a conducting state; the master cylinder isolation valve is energized, and the valve changes from conducting to closed; the test normally open valve is energized, and the valve changes to a closed state; the pedal simulator valve is energized, and the valve changes to a conducting state. Finally, a closed environment is formed in the hydraulic circuit of the on-line brake control system (such as Figure 1 the bold circuit in Figure 2 ). The permanent magnet synchronous motor rotates, drives the rack to move, and then increases the pressure of the secondary master cylinder. Through the hydraulic circuit, it acts on the pedal simulator through the pedal simulator valve. The curve of the simulated pedal force and pedal stroke at this time is as shown in Figure 3 Pedal Force 2 in Figure 2 .

[0045] The pedal feel adjustable electro-hydraulic braking system of the present invention controls the rotation of the permanent magnet synchronous motor, drives the rack of the secondary master cylinder to move, and then increases the pressure of the secondary master cylinder. Combined with the valves to form a closed circuit, the pressure in the secondary master cylinder is conducted to the pedal simulator through the hydraulic circuit; when the driver has a braking demand, since the pedal simulator has been compressed by a certain distance by the brake fluid in the hydraulic circuit, the pedal force felt by the driver when continuing to step on the brake pedal will increase, realizing the effect of the pedal simulator simulating different pedal feels; this system can be realized without changing the structure of the pedal simulator, effectively reducing the cost.

[0046] The above is only a description of the preferred embodiments of the present invention. The above technical features can be arbitrarily combined to form multiple embodiment schemes of the present invention.

[0047] The present invention has been described exemplarily above in conjunction with the drawings. Obviously, the specific implementation of the present invention is not limited by the above methods. As long as various non-substantive improvements are made by adopting the concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. An electronically controlled hydraulic braking system with adjustable pedal feel, comprising a brake pedal, a master cylinder, a pedal simulator, a solenoid valve, a secondary master cylinder, and a drive structure for driving the secondary master cylinder. The brake pedal is correspondingly connected to the master cylinder. The master cylinder is connected to the pedal simulator and the secondary master cylinder through the solenoid valve and a hydraulic circuit. It is characterized in that: The driving structure can adjust the pressure of the secondary master cylinder. By controlling the solenoid valve, different volumes of brake fluid are discharged from the secondary master cylinder and flow to the primary master cylinder. Different pressures are generated after the brake fluid enters the primary master cylinder and are then transmitted to the interior of the pedal simulator.

2. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 1, wherein: The driving structure includes a motor and a transmission mechanism connected to the piston of the secondary master cylinder. A gear connected to the transmission mechanism is provided on the rotating shaft of the motor.

3. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 1, characterized in that: The pedal simulator is connected to the hydraulic circuit through a simulator branch. The simulator branch is connected to the primary master cylinder. The secondary master cylinder is connected to the hydraulic circuit through a secondary master cylinder branch. Pressure sensors are provided on both the simulator branch and the secondary master cylinder branch.

4. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 3, wherein: A pedal travel sensor is provided between the brake pedal and the primary master cylinder.

5. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 3, wherein: A pedal simulator valve is provided on the simulator branch.

6. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 3, characterized in that: Master cylinder isolation valves are provided on both the simulator branch and the hydraulic circuit directly connected to the primary master cylinder. A secondary master cylinder isolation valve is provided on the secondary master cylinder branch.

7. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 6, wherein: When the pedal simulator simulates different pedal feel switches, the master cylinder isolation valve is in a closed state.

8. The pedal feel adjustable electronically controlled hydraulic braking system according to claim 6, characterized in that: The secondary master cylinder isolation valve includes a secondary master cylinder isolation valve I and a secondary master cylinder isolation valve II; The secondary master cylinder isolation valve I controls the connection between the secondary master cylinder branch and the hydraulic circuit. The secondary master cylinder isolation valve II controls the connection between the secondary master cylinder branch and the simulator branch. When the pedal simulator simulates different pedal feel switches, the secondary master cylinder isolation valve I is in a closed state and the secondary master cylinder isolation valve II is in a conducting state.

9. A vehicle, characterized in that: It includes the electronically controlled hydraulic braking system with adjustable pedal feel according to any one of claims 1 to 8.

Images